<template >
  <el-table :data="formatData" :row-style="showRow" v-bind="$attrs" >
    <slot name="firstColumn" ></slot >
    <el-table-column v-if="columns.length===0" :label="labelName" >
      <template slot-scope="scope" >
        <span v-for="space in scope.row._level" class="ms-tree-space" :key="space" ></span >
        <span class="tree-ctrl" v-if="iconShow(0,scope.row)" @click="toggleExpanded(scope.$index)" >
          <i v-if="!scope.row._expanded" class="el-icon-plus" ></i >
          <i v-else class="el-icon-minus" ></i >
        </span >
        {{scope.row.label}}
      </template >
    </el-table-column >
    <el-table-column v-else v-for="(column, index) in columns" :key="column.value" :label="column.text"
                     :width="column.width" >
      <template slot-scope="scope" >
        <span v-if="index === 0" v-for="space in scope.row._level" class="ms-tree-space" :key="space" ></span >
        <span class="tree-ctrl" v-if="iconShow(index,scope.row)" @click="toggleExpanded(scope.$index)" >
          <i v-if="!scope.row._expanded" class="el-icon-plus" ></i >
          <i v-else class="el-icon-minus" ></i >
        </span >
        {{scope.row[column.value]}}
      </template >
    </el-table-column >
    <slot ></slot >
  </el-table >
</template >

<script >
  /**
   Auth: Lei.j1ang
   Created: 2018/1/19-13:59
   */
  import treeToArray from './eval'
  export default {
    name: 'treeTable',
    props: {
      data: {
        type: [Array, Object],
        required: true
      },
      labelName: String,
      columns: {
        type: Array,
        default: () => []
      },
      evalFunc: Function,
      evalArgs: Array,
      expandAll: {
        type: Boolean,
        default: false
      }
    },
    computed: {
      // 格式化数据源
      formatData: function () {
        let tmp
        if (!Array.isArray(this.data)) {
          tmp = [this.data]
        } else {
          tmp = this.data
        }
        const func = this.evalFunc || treeToArray
        const args = this.evalArgs ? Array.concat([tmp, this.expandAll], this.evalArgs) : [tmp, this.expandAll]
        return func.apply(null, args)
      }
    },
    methods: {
      showRow: function (row) {
        const show = (row.row.parent ? (row.row.parent._expanded && row.row.parent._show) : true)
        row.row._show = show
        return show ? 'animation:treeTableShow 1s;-webkit-animation:treeTableShow 1s;' : 'display:none;'
      },
      // 切换下级是否展开
      toggleExpanded: function (trIndex) {
        const record = this.formatData[trIndex]
        record._expanded = !record._expanded
      },
      // 图标显示
      iconShow(index, record) {
        return (index === 0 && record.children && record.children.length > 0)
      }
    }
  }
</script >
<style rel="stylesheet/css" >
  @keyframes treeTableShow {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }

  @-webkit-keyframes treeTableShow {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }
</style >

<style lang="scss" rel="stylesheet/scss" scoped >
  $color-blue: #2196F3;
  $space-width: 18px;
  .ms-tree-space {
    position: relative;
    top: 1px;
    display: inline-block;
    font-style: normal;
    font-weight: 400;
    line-height: 1;
    width: $space-width;
    height: 14px;
    &::before {
      content: ""
    }
  }

  .processContainer {
    width: 100%;
    height: 100%;
  }

  table td {
    line-height: 26px;
  }

  .tree-ctrl {
    position: relative;
    cursor: pointer;
    color: $color-blue;
    margin-left: -$space-width;
  }
</style >
